1. Field of the Invention
The present invention relates to an image forming apparatus and a recording head adjusting method and particularly relates to an image forming apparatus that forms an image by a recording head configured by plural sub-heads and a recording head adjusting method that adjusts shift that has arisen between the sub-heads.
2. Description of the Related Art
A head in a single-pass format image forming apparatus is often configured by plural sub-heads. These plural sub-heads are manufactured as one head as a result of being positioned and attached. Due to misalignment that occurs at the time of attachment, the sub-heads are not attached in ideal positions shown in FIG. 16A, and shift often arises in the attachment positions of the sub-heads as shown in FIG. 16B.
Misalignment of the sub-heads lowers image quality because, as shown in FIG. 16C, shift arises at connecting portions of the sub-heads when ink is ejected simultaneously by the sub-heads. In Japanese Patent Application Laid-Open Publication (JP-A) No. 2005-111990, there is disclosed a technology that corrects by adjusting, in print head units or nozzle units, timings of ink ejection (jetting). This technology addresses print quality deterioration resulting from mutual misalignment between plural print heads. An image that the print heads have drawn is detected with an optical sensor. “x/y/rotation offset” information is acquired. The timings of ink ejection (jetting) is corrected on the basis of that information.